Fluid transmission mechanism



20, 1945. ,D. F. MQGILL 2,369,835

' FLUID TRANSMISSION MECHANISM Filed July 22, 1959 7 Sheets-Sheet 1 FLUID TRANSMI SSION MECHANISM- Filed Ju1y'22, 1939 7 Sheets-Sheet s D.- F. M GILL FLUID TR ANSMISS ION MECHANISM Filed July 22, 1939 7 Sheets-Sheet 4 Feb. 20, 1945.1 D, F, MCGILL 2,369,835

FLUID TRANSMISSION MECHANI SM Filed July 22, 19 39 7 Sheets-Sheet 5.

Feb. 20, 1945; D. F. M GILL 2,369,835

I FLUID TRANSMISSION MECHANISM Filed July 22, 1939 Y-Shets-Sheet e Feb. 20, 1945. McGlLL FLUID TRANSMISSION MECHANISM 7 Sheets-Sheet 7 Filed July 22, 1939 mi a Feb. 20,1945

zasasss mum 'msssmss'ros mzcusmsm Daniel F. McGill, Multnomah County, Oren, as-

signor to Donald Green, Portland, 0reg., as

7 Application July 22, 1939, Serial No. 285,943 I 18 Claims. (01. 6053) This invention relates to a hydraulic or fluid transmission mechanism wherein a fluid medium is employed to transmit torque from a driving shaft to a driven shaft. 4

The primary object of the invention is to provide ailuid connection between a driving shaftand a driven shaft, which connection will perform all the-functions customarily accomplished by the conventional clutch and gear box or an automobile, or bythe clutch and reduction gear- 1 ing of a marine drive or power winch. The transmission is intended for use wherever it is customary to employ'either a fixed or'variable ratio gear train in the transmission of power. A iurther object of the invention is to provide a speed reduction device which will operate at a higher eiliciency andjwith less destructive wear ,on the moving parts, thanv the conventional gear box.

"A further object 0! the invention is to provide an automatic transmission wherein the ratio jchanges gradually, without steps, throughout awide range, in response solely to load conditions, without the intervention of an operator. A still further object is to provide a transmission with a wide range of speed ratios for use where very sensitive and accurate speed control is a prime requisite, and for use with constant speed prime movers such as synchronous gnotors or other non-variable sources of power. 1 In general the transmission mechanism comprises essentially a drive shaft having a single crank and a series of radially disposed pistons and cylinders; a driven shaft in axial alignment with the drive shaft and also having a single crank and'a series of radially disposed pistons and cylinders; and acylindrical casing member the crank in the delivery pump, it being possible to reduce the throw to zero to efiect a neutral" or non-driving connection between drive and driven shafts. Driving ratios intermediate between neutral and direct drive are obtainable by adjustment oi the crank eccentricity just referred to. In the present embodiment, the invention ient and responsive in meeting changing power is illustrated as applied to an automotive vehicle, both manual and vacuum responsive controls being shown for changing the driving ratio in response to power requirements. However, the transmission itself is inherently resildemands, and the external controlling mechanism may be varied to suit the type of-instal- I lation with which this transmission is used.

While the invention is illustrated herein as applied to an automotive vehicle, no limitation is intended thereby, the' invention'being of general application in the field of mechanical power transmission regardless oiwhether the power plant be designed for use in road vehicles, trams,

ships, or stationary installations; and also regardless of whether the prime mover be an internal combustion engine or some other type of motor or engine.

With these and other objects and advantages in view, the invention resides in the novel construction and combination of parts hereinafter described, illustrated in the accompanying drawings and set forth in the appended claims; it being understoodthat various changes in form, proportion, size and details of construction within the scope of the claims may be resorted to without departing 'Iromthe spirit or sacrificing any ofthe advantages of the invention.

carrying both series of cylinders in integral re-.-

I motor cylindersvprovide fluid communication between the various cylinders and fluid chambers contained within theperiphery of the cylindri-r cal casing, and a separate discharge valve on the outlet side ofthemoto'r is provided to establish a fluid lock between the drive and driven fora directdrive.

Means are provided-for varying the throw of the transmission In the fdrawingsz. v Figure 1 is a side elevation of a hydraulic transmission unit embodying the principles of applicants invention as same appears when employed to transmit power from the drive shaft of an internal combustion engine to a driven shaft as man automobile. v

2 is a plan view of the apparatus illustrated in Figure l.

Figure 3 is a sectional elevation of the counterweights at the pump end of the transmission unit, and illustrating the mechanism for controlling the movement thereof, taken on the line 33 of Figure 8.

Figure 4 is a longitudinal unit taken on the line l-Lof Figure2- 7 Figure 5is-a sectional elevation taken transversely of the drive shaft on lines-I of Figure sectional elevation of Y sition.

4, illustrating the mechanism for adjusting the eccentric to vary the stroke of the pistons in the delivery pump.

Figure 6 is a sectional elevation taken transverseiy of the transmission unit on line 6-6 of 'Figure 4, illustrating the position of the eccentric with the pistons of the delivery pump in full couhterweights are rotated when the pistons of I the delivery pump are moved to full stroke Figure 9 is a sectional elevation corresponding to Figure 8, illustrating the position of the counterweights when the pistons of the delivery pump are in neutral position.

Figure .10 is a development of the interior oi the transmission casing on a surface generated by the rotation of the line ill-m of Figure 4 about the longitudinal axis of the casing. The course of liquid, through the device is indicated by the arrows.

Figure 11 is a development of the peripheral surface of one of the cams which operate the valves for the delivery pump and motor, and

showing the relative positions of the motor valves around the periphery of the cam.

Figure 12 is a schematic sectional elevation of the cam for operating the valves for the motor, and particularly ;illustrating the reversing mechanism for operating the valves in timed position and the transmissionof power at zero.

Figures 19 and 20 illustrate intermediate post-- tions of the control elements showing the initial movements thereof for actuating the mechanism to vary the stroke of the pistons in the delivery p p.

Figure 21 illustrates the normal positions of the control elements with the transmission unit fluid locked by a closed control valve, thereby effecting a direct drive between driving and driven shafts.

By way of illustration, the transmission unit is disclosed as applied to a motor vehicle wherein relation with reverse rotation of the driven shaft.

Figure 13 is a sectional elevation taken transversely of the transmission unit on the line l3-l 3 of Figure 12.

Figure 14 is a sectional elevation taken transversely of the transmission unit on the line l4-- H of Figure 12.

Figure 15 is a longitudinal sectional elevation taken on the line I5l5 of Figure 6, illustrating the mechanism for adjusting the eccentric to vary the stroke of the pistons in the delivery Figure 16 is a transverse section taken on the line l6- -l6 of Figure 4, illustrating the bearing for the inner end of the driven shaft and the manner in which the hub of the counterweight for the motor is utilized as a load carrying means. i l

Figure 17 is a fragmentary perspective detail of one of the counterweights for the delivery delivery pump, and for opening and closing the control valve. The respective views illustrate the movement of the parts during various drivthe motor I is equipped with a manifold 2 and a flywheel 3. The transmission is housed in a cylindrical casing positioned between the flywheel 3 and the universal coupling 5 forming a part of the driven shaft 6. At the front or engine end of the transmission unit the drive shaft 7 is bolted to the flywheel 3, and at the rear end of the transmission unit the driven shaft 5 is supported by a bearing 4 carried in the housing of the universal coupling 5, which in turn is supported upon the framework of the vehicle. Exteriorly of the cylindrical casing are outwardly projecting fins 8, each of which traces a spiral path on the external wall of the cylindrical casing. These fins 8 serve as impellers which ccact with the adjacent pan 9 for circulating air over the outer surface of the cylindrical casing, whenever rotative movement is imparted thereto, for dissipating the heat generated in the transmission unit.

At the engine end of the transmission unit the cylindrical casin is closed-by a cover I!) equipped with an oil seal ring H to seal the casing at the drive shaft. Likewise the rear end of the casing is closed by a cover l2 equipped with an oil seal ring [3 to seal the .casing at the driven shaft. The cover l2 also contains the bearing for the rear end of the cylindrical casing.

The cylindrical casing is rotatably mounted upon the drive shaft 1 and the driven shaft 6 by means of bearings 20 positioned at suitable intervals throughout the length of the casing, these bearings supporting the casing by means of open frameworks or spiders 2|; The cylindrical casing incloses a plurality of series of radially disposed cylinders, one of said series being radially disposed about the drive shaft, and another one of said series being} radially disposed about the driven shait. operatively connected to the drive shaft are pistons which operatein the cylinders of the first mentioned series, and'which constitute therewith a delivery pump; and operatively connected to the driven shaft are pistons which operate in the cylinders of the second mentioned-series, and which constitute therewith a motor.

The cylindrical casing comprises an outer wall I and an inner wall Hi, the space therebetween, with the exception of that occupied by the pump and motor cylinders, 'being divided into a suction chamber IS, a pressure chamber l1 and a discharge chamber l8. Within the space defined by the'inner wall l5, excepting as this space is occupied by the pump and motor assemblies, is the reservoir l9 to which fluid is returned from the discharge chamber l8 by way 9f the control valve, presently to be described.

.From thereservoir IS the fluid is delivered to the suction chamber N by means of a centrifugal pump 22 keyed to the drive shaft 1 adjacent the engine end of the casing. From the suction chamber IS the fluid is admitted toeach of the cylinders 23 of the delivery pump by way of aclosed to both intake and discharge and the pisvalve 24, and from each cylinder 23 of the delivery pump the fluid is discharged by way of' the same valve 24 into the pressure chamber I'I, each valve 24 functioning both as a suction valve and as a discharge valve. The valves 24 are operated by a cam 28 which engages a groove 33 in each valve stem 21, the manner of operation .which is presently to be described.

Each of the valves is of thepiston and cylinder type. Each valve is formed with a peripheral groove which is at all times in communication with the cylinders, and which provides commu-- nication between the cylinders and the intake and discharge ports, respectively, as the valve is actuated to open andlose these ports. Inasmuch as each valve operates to admit fluid to the respective cylinders, and to permit the discharge of fluid from the cylinders, each valve performs the functions of two valves of the conventional type. The construction and operation of the valves will best be understood by reference to Figures 4 and 10. It will be noted that the channels or grooves in the valve casing which form the intake and discharge ports are so designed that the pressure of the liquid is applied equally around the periphery of the valve. Likewise the pressure of the liquid in the peripheral groove is exerted equally in all directions of the valve and irrespective of what this pressure may be the valve is balanced.

Each of the valves is equipped with a relief valve positioned within and forming an integral part of each valve structure; These elief valves comprise a passage 32 communicating with the peripheral groove in the valve, which passage is closed by a ball 33 normally held in position to close the passage 32 by a spring 34. The spring 34 is seated in a retainer 35 threadedli engaging the valve, the adjustment of which retainer predetermines the pressure necessary to lift the ball 33 of! its seat and permit the flow of liquid from the peripheral groove through the passage 32 into the fluid reservoir 19 in the interior of the easing.

Each of the valves is operated in timed relation to the movement of the pistons in the repective pump or motor cylinders by means of cams which operate the valves by engaging a groove in each valve stem. During one complete revolution of each cam, each valve operated thereby is moved into position in which the intake portis in regis-e try with the passage-communicating with the respective pump or motor cylinder, and from thence into position in which this passage is in communication with the output port, and from this ton-is on dead center at the bottom of its stroke. During continued rotationof the cam through the next 60 the valve opens to discharge during the upward stroke of the piston, and is'wide open or in position affording full communication between the passage communicating with the cylinder and the discharge portion a period of 60 rotation, from which point thevalve againreverses direction as the piston reaches the top of its stroke at the point of A development of the periphery of the cam 43, which operates the valves 38 for the motor, is illustrated in Figure 11. It will be noted that the positions of the valve stems 4!! correspond to the positions of the valves for the motor cylinders 31 shown in Figare 10. The cam 43 is driven by-a mechanism which permits it to function also as a reversing Y mechanism,presently to be described. The cam 26, which operates the valves 24 for the delivery pump, is bolted to the centrifugal pump 22 keyed to the shaft '1 and is rotated thereby.

- The cam 43 which operates the valves 38 for the motor comprises the peripheral edge of a disc 41 which functions as a reversing'mechanism for reversing the action of the pistons 85 in the motor cylinders to cause the vehicle to'be driven in a reverse direction. To accomplish this the disc is rotated relative to the driven shaft 5 so that a point on its peripheral surface is removed a distance of 180 from its position when the vehicle is being driven in a forward direction. When the cam is thus rotated 180 the operation of the valves 38 is reversed and'the pistons of the motor are caused to drive the driven'shaft in reverse direction. The reversing mechanism is in the form ofa disc 31, the peripheral edge of which constitutes the cam 43 which operates the valves 38 by engaging grooves 48 in the valve stems 39. The

last named position to the starting point first from the pressure chamber H by way of the pass- I to be at 0", the peripheral groove in a valve operated by the cam is clbsedto both intake and discharge, and is in communication only with the passage communicating with its respective cylinder. At this moment the piston in the corresponding cylinder is on dead center at the top'of its stroke. During rotation of the shaft a dis stance of 607 from this point the valve is being moved into a full open position, aflording-communication between the intake port and themesage communicating with thecylinder. This position is maintained for 60? of rotation of the shaft. At this point the valve begins its reverse stroke and fat the 180 position the'valve is again disc 4! and the cam 43 are driven by a stud 50 forming a part of the driven shaft, which stud drives against the end of a semicircular groove 5! milled in the face of the reversing disc 41; Fluid from the pressure chamber I1 is admitted'to the groove 5| by way of passages 52a or 52b and is ex hausted from the groove 5! into the reservoir is by way of exhaust passages 53a or 5317, according to the position of the reversing valves 54a and 54b. This structure is best illustrated in Figures 12 and 13. The reversing valve 54a is provided with intake port 55 and exhaust port 56. In valve 34b one port H8 serves as either intake "port or exhaust port according tov the position of the valve. In Figures 12 and 14 the setting of the reversing valves Sla and 54b is such that the vehicle is being driven in a forwarddirection. In this position fluid is admitted to the groove 5| sage 52a, valve 54:: and communicating passages 51a. Fluid is exhausted from the groove 5| by way of communicating passages 51b, valve 64b and exhaust passage 53b. To rotate the disc 41 to cause the vehicle to be driven in reverse, the

valves 54a and 54b are moved into the position wherein fluid from the pressure chamber I1 is ad mitted to the groove 5| through the passage 52b,

valve 54b and communicating passages 51b, and

fluid is exhausted from the'groove 5| through communicating passages 51a, valvejla-and exhaust passage 53a; The setting of the'valves determines the direction from which pressure is ad-'- mitted to the groove 5] and so determine the r gllil ative position of the reversing disc 41'. when the fluid is admitted to the space between the stud so and the adjacent end of the groove ii, the end of the groove is forced away from the stud 50 and so rotates the disc 41 until-the opposite end of the groove 5| contacts the opposite edge of the stud. The-reversing disc is thereby rotated 180 to change-the timing of the valves 38 to cause the shaft B'to be driven in the opposite direction. The valves 54 are operated by means of valve stems 58 which project through the rear cover l2 and are operated by a mechanism presently to be described Fluid is admitted to the pump cylinder 23 from the suction chamber Is by way of an intake port 29, and is discharged fromthe pump cylinders 23 to the pressure chamber I! by way of the output port 30. These ports are designed to be brought into communication with the pump cylinders 23 by way of peripheral grooves 28 in each valve 24 shaft and designed to be moved longitudinally thereover between the front cover in and the housing for the flywheel 3. The shaft I is slotted and passages 3| communicating with the pump I cylinders. As has been stated, the intake port 29 and the output port 30 form grooves in the wall of the valve casing so that the pressure of the liquid in each groove is applied equally around the periphery of the valve. Likewise the passage 3! communicating with the pump cylinders forms a, groove in the wall of the valve. casing in the same manner as do the intakeand output ports.

The pressure chamber I1 is in communication with the output ports 30 of each of the pump cylinders, and is also incommunication with the intake ports 40 for each of the motor cylinders, so that fluid discharged from any one of the pump cylinders 23 may be admitted to any one of the motor cylinders 31. This may best be understood by reference to Figure 10, wherein it will be seen that the pressure chamber, as do all of the fluid chambers, extends all the way around the casing. From the pressure chamber I! the fluid enters the motor cylinders 3l by way of valves 38, the construction of these valves being identical with'that of the valves 24 for the delivery pump. The intake port 40 and outputport 42 for the motor cylinders, together with the passage ll communicating with the motor cylinders fl, form channels or grooves in the valve casing, as hereinbefore described in connection with the description of the valves 24 for the pump cylinders, so that pressure is applied equally around the periphery ofeach valve 38. Pressure admitted to the peripheral groove 39 in each valve 38 is exerted equally in all directions, creatin a balanced valve.

From the discharge chamber 18 the fluid is exhausted to the reservoir I! interiorly of the casing by way of ports 44 which are opened and closed by means of a control valve 45 having ports 48,

adapted to be brought into registry with the discharge ports 44. The control valve 45 is best illustrated in Figures4, 12 and 13, wherein it will beseen that it is in the form of a ring closely fitting the inner wall of the casing and having a multiplicity of the ports 46 opening therethrough.

The valve is so designed that when pressure is applied thereto, as when the valve is being opened or closed, the valve is balanced and is readily responsive to its control mechanism. Because of the multiplicity of ports I opening through the wall of the valve, fluid discharging from the discharge chamber II to the reservoir I! has a balanced reaction on the valve, the pressure app lied thereby exerting no end thrust action on the valve.

For a portion of its length the drive shaft 1 is hollow, and slidably mounted therewithin is a spirally threaded nut 50 to whichis secured an mating sleeve I slidably mounted upon'the as at 6| to receive the pin 62 for interconnecting the nut 59 and the sleeve 60. The nut 59 engages a spirally threaded shaft 63 and is the means by which the shaft 63 is turned about its axis. Adjacent the inner end of the shaft 63 is an eccentric 64 rotatably mounted in a bushing 65 which is slidably mounted in a'recess 13 in the block 12 and permitted limited movement transversely thereof. As the shaft 63 and eccentric (it are rotated by movement of the nut 59 this bushing 65 moves from side to side of the recess E3 to permit rotative movement of the eccentric t l. By reason of the construction just described movement of the actuating sleeve 60 in a direction toward the cover In causes rotation of the shaft 63, which in turn displaces the eccentric from the neutral position illustrated in Figure 7 into the full stroke position illustrated in Figure 6. It will be appreciated that between these two points there is a considerable range of degree of eccentricity to-which the eccentric may be moved. Inother words, the axis of the eccentric may be brought into axial alignment with the drive shaft 1 or moved out of alignment therewith by rotation of the shaft 63 whereby the degree of eccentricity may be varied from zero upwardly,

It will be noted that the nut 59 on the shaft 63 is mounted eccentrically of the shaft 1, and that likewise the opposite end portion of the shaft 63 is eccentrically mounted in the bushing I20 which is designed to transfer the load of the drive shaft assembly to the bearing 20 at the inner end of the shaft. As illustrated in Figure 15, the shaft 63 has been rotated to move the eccentric 64 into the position of greatest eccentricity, which is the position also illustrated in Figure 6. In Figure 15 the center line of the shaft 1 is the center line of rotation. The center line of the eccentric 64 is the axis of the piston assembly and the distance of the center line of the eccentric 66 from the center line of the drive shaft 1 is equal to one half the length of stroke of the pistons in the delivery pump. Movement of the actuatin sleeve 60 toward the vehicle engine serves to rotate the shaft 63 relative to the shaft 1 and moves the eccentric 64 into axial alignment with the shaft I, thus bringing the pistons of the'delivery pump into neutral position. In neutral position the block 12 is in axial alignment with the drive shaft 1 and functions merely as a bearing for the connecting rods.

Each of the pump cylinders 2 3 is provided with a piston 25' and these pistons are actuated by connecting rods 66 which are connected with cured by means of collars 6 with the drive shaft 1 to vary the stroke'of the pistons 25 in the delivery pump causes the axis of the piston assembly tobe moved out of axial alignment;.with the center ofrotation, thereby destroying the balance of the transmission unit. To overcome this dimculty applicant has provided counter-weights I4 and II which are rotatable aseaesa I controls the mechanism for operating the control relative to the drive shaft-to counterbalance the eccentricity oi the piston assembly, Reference to Figures 3, 8, 9 and will disclose the fact that each of these ccunterweights. is made in 'the shape of a segment -oi',a circle and that they. are mounted in overlapping or face to face re- -1ation attheir centers. "Whereat' they are mounted onthe bushing I20, whereas-their major portions valve 45. This valve 94 is open to the atmosphere are in alignment transversely-oi the transmission unit. For controlling the movement of these counterweights there is secured to the block I2,

as by a pin 15, a plate TI. This plate 11 has driving engagement with the bushing I by means of a tongue and groove connection I8. A1 flxed to the plate "at one side of the bushing 120, so as to project into a recess I9 in the counplate TI causes .the pins 90 and BI to rotate the I respective counterweights actuated thereby. about the axis of the bushing I20. By this mechanism there is imparted to the counterweights' a, rotative movement in timed relation to the displacement of the piston assembly from'a coaxial or neutral position, thereby counterbalancing the through one end thereof, andis opened and closed by a piston 96 to which is connected a piston rod 91. The rod 91 is secured to a foot pedal 99 which in turn is under control of a piston 90 in the vacuum unit 93. A piston rod I2I interconnects the foot pedal 99 andthe piston-98 in the vacuum unit 93, and intermediate its length the rod I2I is secured to a lever I00 having a bifurcated arm |0I adapted to engage .and move the actuating sleeve 60. By this means, whereby the control elements are mechanically connected to the foot pedal 99, the operation of the vehicle may be manually controlled. "-A pipe line I02 intercom nects the valve 94 and an auxiliary vacuum unit I09, operable within which vacuum unit I03 is a piston having a piston rod I04 secured to a bifurcated lever' I05 designed to operatively engage a grooved control member I09 for operating the control valve 45. I tained in extended position (in which. position the control valve is open) by a tension spring piston assembly whenever same is moved out of coaxial alignmentwith the center of rotation. when the axis of the eccentric is in axial alignment with the shaft I, so that the pistons are in neutral position illustrated in-Figure 'I, the positlon of the counterweights 14 and I5 corresponds to that illustrated in Figure 9. a When the eccentric has been displaced so that the piston assembiy is moved into full .stroireposition 8.311?" alustrated in 6, the counterweightsIassume theposition illustrated. in Figure 8.

v The piston-assembly upon a iixed eccentric ,vided a counterweight 04 keyed tothe driven for the motor is mounted 99 and to counterbalance v the offset position 01' thefpistons there is pro- I01 and is moved against the force of the spring I01 by the vacuum created by the engine whenever the piston position to allow communication between the 'pipe line I02 and .the pipe line 95 leading to 99 in the valve 94 is moved into the manifold. A pipe line I09 communicating with the vacuum tank 9| is equipped with a shut off valve I09 on the instrument panel of the vehicle and from thence leads to a port midway of the slide valve 92s The slide valve 92 is open to the atmosphere at both ends thereof and is equipped with a double ended piston IIO adapted to be moved in one direction (to the left in Fi ures 18 to 21) by a compression spring III; and

in the opposite direction by a flexible cable 2 -attached to the end of a pin II 9 which projects shaft 9. Since the eccentricity of the as- 'sembly for the motor is invariable, the counterthe v slide valve 92.

weight. is mounted permanently in nxeiirel'a- 3 tion thereto. The motor cylinders 11 are equ pped with pistons 00 which are actuatedby connecting rods 90, the pistons being": thereto as by means of wrist pins 01. The inner The length of stroke of the pistons in the delivery pump, and the operation of the control valve, may be controlled by mechanism operable either manually by the operator of the vehicle or by mechanism operated entirely by the vacuum created bythe vehicle engine, or by a combination of manually and automatically op-' erated controls. The control mechanism illus V trated on the accompanying drawings includes the manifold 2, a vacuum tank 9I connected therewith, a; mechanically operated slide valve 192, and a vacuum unit 93. Air is exhausted from the .vacuum tank 9| through the pipe line 95. Connected into the pipe line 95 is a valve 94 which the bushing as y ve' n of the co'nnectingrodg 5| are m m 1 0fvehicle has' been stopped, and the transmission circular segments 09 designed to have arcuate 5 sliding movement overa, bushing forming a;

ended p i n through the ioot'pedal' 99 and by means of which the cable I I2 may be actuated to move the piston IIO against the action of the spring III. A pipe 'I I4 connects the inner. end of the vacuum unit 90 and a port midway or the slide valve 92; and a u'nication between the op-.

pipe lilpr vid Y i of the vacuum unit 93 and posite or outer end To bring, the mat-ta t stop the pin. a

' mm the slide valve 92 m opposi- =tion"to the action'oi the spring II I. The respecitions of the control elements when the i P wer is at zero, is illustrated in Figure 18, in which positions the control elements have: op-

disconnect thefdrive shaft from the shaft.

Downward movement of the pin II9 moves th double ended piston I I0 into positicn'wherein air is admitted to the outward end of the vacuum unit 99 through the pipe I-I while the inner end of the vacuum unit 93 .is p aced in communication with the vacuum closed to avoid drawing end of the vacuum unit and I I4. Movement of the piston 99" in response vto the vacuum, created in the inner end or the- -vacuum imit 93 causes the rod I2I to so move -the lever I00 as to cause theactuating sleeve tobe moved toward the flywheel 9, whereby the shaft 00 is rotated to bring the eccentric 04 into axial alignment with the drive placing the'piston inxneutral position. Thereupon the valve I09 is 93 when the pin II! is released and consequent movement of the double The piston 'rod' I04 is mainis moved downwardly, thereby moving the double tank 9| through pipes I09 shaft 'I,"t1 1erebyv ssembly of the delivery pump 7 a vacuum in the outer position. J

.After the vehicle is in operation, the operationended piston H in response to the action of'the spring III provides communication between the line I08 and the pipe II5.

It should be stated that'the foot pedal 99, by and of itself, is not actuated by the operator. Rather, the foot pedal is under controlof the piston 98 in the vacuum unit 93. For example, when the operator depresses the pin I I3, the foot pedal 99 moves downwardly to the fioorboard, this movement, however, being due to the movement of the piston 98 as air is exhausted from the inner end of the vacuum unit 93 and the outer end thereof is opened to the atmosphere through the pipe H5. Likewise, it is true that the foot pedal follows'the operators foot upwardly, but this is due to the fact that as the pin H3 is released, movement of the piston 90 is reversed as air is exhaustedfrom the outer end of the vacuum unit 93 and the inner end thereof opened to the atmosphere through the pipe IM. 1

Movement of the piston 99 toward the inner end of the vacuum .unit 93 operates to move the p piston 90 in the valve 94 toward the closed end of the valve and opensthe end of the pipe .line I02 to the atmosphere.

the auxiliary vacuum unit I09, the piston rod I06 Air being admitted through the pipe line I02 into the closed end of is moved to extended position by the spring I01, 1 thereby causing the bifurcated lever I05 to move I the control member I06 and cause the'control valve 45 to move into position to open the exhaust ports 4 thus permitting fluid to circulate from the discharge chamber I8 into the reservoir I9.

To begin movement of the vehicle the operator must first depress the pin I I9 and open the valve- I09. Thereupon the operator slowly raises his foot, thereby releasing the pin H3 and allowing the spring I II to move the double ended piston H0 into position whereby air is admitted to the inner end of the vacuum unit 93 through the pipe H4, while the outer end of. the vacuum unit 93 is placed in communication with the vacuum tank 9| through pipe lines I I5 and H38. As the foot is raised (Figure 20) the vacuum created in the outer end of the vacuum unit 93 moves the piston 98 toward the outer end of the vacuum 'unit 93 which in turn imparts movement to the lever I00, thereby moving the actuating sleeve 50 toward the transmission unit and rotating the shaft 63 to move the eccentric out of axial alignment with the drive shaft I. Thereupon displacement of the piston assembly in the delivery pump will cause the delivery pump to commence the delivery of fluid under pressure to the 'motor. It will be noted that not until the-piston 98 in the vacuum unit '93 is in its fully extended position is the valve 94 opened by outward movement of the piston 96 to permit communication between the pipe line I 02 and the manifold 2, whereby vacuum is created in the inner end of the auxthe spring I01 andmove the lever I05 to cause is important that the control valve be not closed until after the piston assembly for the delivery pump has been moveddnto full stroke exhaust ports 44 the transmission unit is fluid locked, and the delivery pump and motor and cylindrical casing rotate as one unit at the same speed. as the drive shaft I with no moving parts therewithin. This condition prevails when the control elements are in the positions illustrated in Figure 21. In the event of a lessening of the vacuum created by the vehicle engine, in which case the tension of the spring I0'i -is sufficient to overcome the vacuum at the lnnenendcf the auxiliary vacuum unit I 03, the spring acts to overcome the pull of the vacuum and moves the lever I05 which coacts with the control member I06 to open the control valve 955. Thus movement of the control valve is governed by the amount of vacuum created in the manifold.

A check valve II 6 in the line 95 prevents a lessening of the vacuum created in the tanl: Ell

so that the vacuum in the outer end of the vacuum unit 93 is not disturbed by sudden changes of the vacuum created in the manifold. Therefore; because a constant vacuum is maintained in the vacuum tank 9i and exerts a constant pull on the piston 98 in the vacuum unit 93. the length of the stroke of the pistons in the pump cylinders is not affected by the increase or decrease of vacuum in the manifold of the en 'gine.

Operation Eluid is introduced into the cylindrical casing by way of ports Ill in an amount suficient to practically fill the casing, leaving room, however,

, for expansion of the fluid.

When starting the motor it is necessary either that the shut off valve I09 be closed, or thatthe pin I I3 be depressed to open the slide valve 92 to place the inner end of the vacuum unit 93 in communication with the vacuum tank 9i through pipes l I4 and I09. Thus the eccentric tfl'is maintained in axial alignment with the drive shaft and the piston assembly of the delivery pump is in neutral position. However, rotation of the drive shaft I operates the centrifugal pump 22; and the cam 26, and fluid is delivered to the suction chamber I5 under pressure sumcientto sup- 24 at once times the valves so that they open the motor.

and close in proper relation to the stroke of the pistons in the pump cylinders. Thereupon, as the delivery pump begins operation, fluid is admitted to the pump cylinders from the suction chamber and is discharged therefrom into the pressure chamber for delivery to the cylinders of With the pin II3 depressed and the foot pedal 99 at the floor board, the shut 01f valve I09 may be opened, whereupon the vehicle, may be placed in motion by raising the foot and permitting the pin II3 to return to extended position. If the pin H3 be released momentarily and then again be depressed, the piston II! in the slide valve 92 may be moved into position to close both the pipe I I4 and the pipe 'I Is. This action will serve to the control member I08 to close the valve 45. It

first relieve the vacuum in the inner end of the vacuum unit 93 and partially exhaust the air from the outer end thereof, and thereupon close the vacuum unit to both suction and air. when this occurs, the pistonin the vacuum unit 90 will be held in an intermediate position and the piston assembly in the delivery pump be displaced to a degree intermediate its neutral and full stroke positions, at the will of the operator. The effect is to maintains desired driving ratio higher than that to be obtained when the piston assembly is in full stroke position. To secure this result it is necessary that the pin III be held in length of stroke of abe varied from zero ot the operator the ability of the vehicle engine road requirements. a By mounting a simple clutch mechanism (not shown) between the vehicle engine and the manipulated to operate d v nerby means of a .brake lever I21. During all accuses the intermediate position above mentioned. If the pin H8 be permitted movement pump will be moved As has been stated, the drive shaft delivered by the casing in the-manner of a into full stroke position.

the impeller. 22 is'keyed to impeller 22 reacts against the turbine and drives the uninterrupted upward the piston assembly in the delivery- 'I and is driven thereby. The fluid vention hereinabovedescribed is illustrated for to limitthe application of the invention thereto. Neither is it intended tolimit the application of the invention to a construction in which the pis-' casing in the forward direction. The relative ro- I tation of the cylindrical. casing with reference to the drive shaft, together with the length of stroke -of the pistons in the delivery pump, determines the volume of fluid delivered by the delivery pump [to the motor. The speed of rotation of the driven shaft is determined by the volume of fluid de-.'

livered to the motor and the speed of rotation of the casing. After the pistons of the delivery pump are in fullstroke position the driving ratio between the drive shaft and driven shaft is determined entirely by the load on the vehicle engines The displacement ratio of 'the delivery pump with respect to the motor is as 1:2, which is obtained in the illustrated embodiment by usin pistons of equal diameter in both pump and rnotor, and giving to the motor pistons a stroke of- Y the pistons of the delivery.

two inches and to pump a full stroke of one inch. By varyingthe pump from zero upwardly,

delivery pump have been moved into full "stroke position, the drivingratio is controlled automaticallybe means of the mechanism whichcontrols on) movement of the control valve '45, byvirtue of the changing rotational speed of the casing as the the pistons in the delivery the driving vratio'may upwardly. After the vehicle j' has been put in motion, and the pistons of the either in its entirety or in part, and either with 'of the delivery pump,

use in an automotive vehicle, it is not intended tons of the delivery pump and motor have a stroke of specified lengths; or inwhich-it is im- 7 perative that the length of stroke of the pistons ratherthan of the pistons for the motor, be variableto create a driving ratio. I In other words it isclearly within the purview of the invention that the length of stroke of the pistons in the motor be governed by a control mechanism, instead of, was well as, the length of stroke of the pistons vofth'e delivery Furthermore, the invention maybe used,

or without modification, for industrial and. ma-

rine. purposesas well,: and with prime movers other than internal I deem myself entitled to all such uses, modifications'and/or variations as fall within the spirit and scope of the appended claims.

*Having now described my invention and in I what manner the same may be-used, what I claim as new and desire to protect by Letters Pat-I entis:

l. -In a fluid transmission mechanism having a drive shaft with a radial cylinder and piston fluid 1 pump assembly thereon,- a driven shaft with a control valve restricts the fluid flow to varying degrees. These last'mentioned changes in driving ratio are effected without the intervention and are. solely dependent upon and 54b to cause fluid groove il in the face of the reversing disc to meet the L gre ssively close the manner .hereinbefore described. The valves are connected to a grooved collar I23, which is under control of a bifurcated arm I24 designed to engage in the groove. and the lever iaare'connected by suitable link; age (not shown) when the operation of the -,valves 38 for the motor'ha's been timed to cause driven in a reverse dithe driven shaft 8 t be rection, it becomes necessary toapply a brake I25 to hold the .casing stationary.) .The brake I25 brake drum I26 bolted to the cyling and'is operated in an ordinary manengages times that t'he vehicle is being driven backwards, the control valve 55 is held-open to permit circulation of fluid from the motor cylinders to the reservoir-l0.

The bifurcated Ill trolling the flow of fluid through said said control valve,

radial cylinder and piston fluid'motor assembly thereon, movable means to vary thecrank throw of the pump pistons and avalve to control the pumpedv fluid and when closedto establish a fluid looked condition, a iirst vacuumv cylin er to operate said mov'ablemeans, a manually operable selector valve to control said flrstvacuum 4 cylinde a second vacuum cylinder to operate and a second selector valve operated by said first vacuum cylinder and said movable means to cause said second vacuum cylinder to. close said valve only when said movable means is in a predetermined position, whereby the fluid locked condition will not occur until said movable means has produced a predetermined crank throw.

' 2. In a fluid transmission mechanism havin a member movable between two' extreme positions -to vary the transmission ratio, and a valve to control fluid -flow inthe transmission, a control system comprising said movable member to a selected position and to maintain said selected position, means to prosaid valve to a selected position, and means operated by said flrst-naniedmeans to prevent the actuation of said valve-closingmeans .until said movable member is in one of its ex-.

treme positions, said valve closing means, when actuated, being responsive to a predetermined operating condition of said fluid transmission.

s. A torquesehsitive' fluid transmission com- I prising a driving me'mberg'a fluid pump connected to said driving membenmeans for eifective displacement of said. fluid pump, a

driven member, a motor connected to said driven 1 member, said motor being'operated by fluid dclivered by said pum for driving said driven member, conduits joining the pump and motor for conducting fluid therebetween. a: valve forconpump and fluid lock the transmission motor and operable to drive betweendriving and unit to create a direct driven members. vacuum cylinder means for urs-,

Although the particular embodiment of the incombustion engines, without departing from the spirit of the invention;' and "means to progressively move varyin g the tion for maximum displacement.

moving said valve means to said one position only after said fluid pump has been placed in posi- 4. In a fluid transmission mechanism, a tubu lar drive shaft and a driven shaft, a series of cylinders arranged radially about each of saidshafts, pistons operating in said cylinders and operatively connected to their respective shafts, a spirally threaded auxiliary shaft extending axially of said tubular shaft, an eccentric carried'by said auxiliary shaft, a nut within said tubular shaft having engagement with the threads of said-auxiliary shaft, an actuating collar slidably mounted on the drive shaft, means interconnecting the collar and said nut whereby movement of the collar causes a like movement of the nut and rotates said auxiliary shaft, and a cylindrical block mounted on said eccentric and movable laterally of said transmission unit by rotation of the eccentric, the pistons for one of said series of cylinders being connected to said block whereby rotation of said auxiliary shaft causes a variation in the length of stroke of the pistons in said cylinders.

5. In a fluid transmission mechanism, a tubular drive shaft and a driven shaft, a series of cylinders arranged radially about each of said shafts, pistons operating in said cylinders andoperatively connected to their respective shafts, a spirally threaded auxiliary shaft extending axially of said tubular shaft, an eccentric carried by said auxiliary shaft, a nut within said tubular shaft having engagement with the threads of said auxiliary shaft, an actuating collar slid-" "ably mounted on the drive shaft, means interconnecting the collar and said nut whereby movement of the collar causes a like movement of the nut and rotates said auxiliary shaft, a cylindrical block mounted on said eccentric and movable laterally of said transmission unit by rotation of the eccentric, the pistons for one of said series of cylindersbeing connected to said" block whereby rotation of said auxiliary shaft causes a variation in the length of stroke of the pistons in said cylinders, a counterweight for counterbalancing said pistons, said counterweight being rotatable relative to said shaft, and means into and out of coaxial alignment with the shaft to vary the length of stroke of said pistons in said cylinders, a counterweight for counterbalancing said pistons, said counterweight being movable relative to said shaft, and means for moving said counterweight simultaneously with the movement of the crank into and out of co axial alignment with said shaft.

8. In a fluid transmission mechanism, a shaft rotatable therewithin, a variable throw crank on said shaft, a series of cylinders arranged radially about said shaft, a piston operating in each of said cylinders and operatively connected to said crank, means for moving said crank into and out of coaxial alignment with said shaft for varying the stroke of the pistons in said cylinders,

a counterweight for counterbalancing said pistons, said counterweight being adjustable relative to said pistons according to the degree of cocentricity of said crank with respect to said shaft, and means within said transmission unit for controlling the adjustment of said counterweight.

9. In a fluid transmission mechanism, a drive shaft and a driven shaft, a delivery pump operatively connected to the drive shaft, a motor operativelyconnected to the driven shaft, a cylindrical casing enclosing said pump and said motor and rotatable relative to said'shafts, a plurality of fluid chambers arranged circumferentially of said casing and communicating with said pump and motor, a fluid reservoir disposed centrally of said casing, a pump for pumping fluid from said reservoir to one of said chambers, and a valve for controlling the flow of fluid from another one of said chambers to said reservoir.

10. In a fluid transmission mechanism, a driving shaft carrying pistons, a driven shaft in axial interengaging said block and said counterweight for rotating said counterweight about said shaft 1 as the block is moved by rotation of said eccentric.

6. In a fluid transmission mechanism, a drive shaft anda driven shaft, a series of cylinders arranged radially about each of said shafts, pistons operating-in said cylinders and operative-1y connected to their respective shafts, an eccentric I carried by oneof said shafts, means for adjusting the eccentricity of said eccentric to vary the stroke of the pistons in one of said series of cylinders, a counterweight for counterbalancing the pistcns. operated by said eccentric, said counterweight comprising two elements mounted for limited rotation about said one shaft, and means for rotating said elements simultaneously with the adjustment of said eccentric.

7. In a, fluid transmission mechanism, a drive shaft and a'drivenshaft, a variable throw crank -on saiddrive shaft,'a series of cylinders arranged radially about said drive shaft, pistons operating in each of said cylinders andoperatively connected to said crank, said crank being movable alignment therewith also carrying pistons, a cylindrical casing rotatable about both of said ,shafts, said casing containing cylinders in one end coacting with the pistons on the drivin shaft to form a delivery pump and containing cylinders in the other end coacting withthe pistons on the driven shaft to form a receiving pump or fluid motor, the piston displacement of said motor being different from the piston displacement of said deliyery pump, fluid passageways establishing a hydraulic connection between said delivery pump and said motor, and a valve to control the fluid flow from the motor cylinders, whereby torque may be transmitted from the driving shaft to the driven shaft in automatically varying ratios in accordance with the torque requirements of the driven shaft.

11. In a fluid transmission mechanism, a drive shaftand a driven shaft, a series of cylinders arranged radially about each of said shafts, pistons operating in said cylinders and operatively connected to their respective shafts, said drive shaft and pistons and cylinders constituting a pump and said driven shaft and pistons and cyl- I inders constituting-a motor, said two series of cylinders being integrally joined for common rotation about said shafts, and a valve for controlling the flow of fluid from the motor cylinders and operable to fluid lock the transmission mech-' anism to create a. direct drive between driving and driven shafts.

12. A torque sensitive fluid transmission comprising a casing, a driving member, a fluid pump connected to said driving member, a driven memher, a motor connected to said driven member, said motor beingi operated by fluid delivered by said pump for driving said driven member.

means defining a plurality of fluid chambers arranged within said casing, a valve for each said pump and motor and having separate'port means providing communication between each said pump and motor and at least two of said fluid chambers, each said valve comprising a cylinder having means defining three substantially annular ports, and a piston-like member mounted within said cylinder having a substantially annular recess of such width as to uncovenadjacent two of said ports. said piston-like member being movable to one position to provide communication between one of said chambers and said pump or motor. and being movable to a second position to provide communication between the other of said chambers and said pump or motor.

13. In a fluid transmission mechanism. a drive shaft and a driven shaft, a delivery pump operatively connected to said drive shaft, a motor operatively connected to said driven shaft, a cylindrical casing enclosing said pump and motor and rotatable relative thereto. aplurality of fluid chambers arranged circumferentially of said casing and communicating with said pump and motor. a valve for controlling the flow of fluid 4mm said motor. said valve comprising a cylinm-u-al sleeve having port means in substantially annular arrangement therearound and a second cylindrical sleeve closely fitting said first cylindrical sleeve and movable therewithin to cover said port means. and means to cause relative movement of said sleeves to open and close said ports.

14. In a fluid transmission mechanism having a plurality of cylinders disposed about a shaft,

valves for said cylinders, operating means for said valves comprising a cam plate mounted on said shaft for limited relative rotation with respect thereto. an arcuate channel in one face of said cam plate concentric with and extending part way around said shaft, a stud on said shaft disposed within said arcuate channel and limitingthe said relative rotation of said cam plate, a fluid duct opening into each end of said arcuate channel. and means for applying fluid pressure to each of said ducts selectively to effect said relative rotation of said cam plate.

15. In a fluid transmission mechanism, a plurality of cylinders disposed about a shaft, valves or said cylinders controlling the intake and egress of a fluid medium, means for operating said valves comprising a cam member carried by said shaft and shiftable to either one of two positions on said shaft to time said valves for either forward or reverse rotation of said shaft, respectively, and controllable fluid pressure means for shifting the position of said cam selectively to either of its two positions.

16. In a fluid transmission mechanism, a drive shaft and a driven shaft, a series of cylinders disposed about each of said shafts, said two series of cylinders being integrally joined for common rotation about said shafts, valves for said cylinders controlling the intake and egress of a fluid medium, means for operating the valves for the cylinders of one of said series comprising a cam member carried by one of said shafts and shiftable to either one of two positions to time said valves for either forward or reverse rotation of said shaft, respectively, means for shifting the position of said cam selectively to either one of its two positions, and means for arresting the rotation of said cylinders about said shaft.

17. In a fluid transmission mechanism, a drive shaft and a driven shaft, a delivery pump operatively connected to said drive shaft, a motor operatively connected to said driven shaft, a cylindrical casing enclosing said pump and motor and rotatable relative thereto, means defining a plurality of fluid chambers arranged within said casing, a valve for each said pump and motor having separate port means providing communication between each said pump and motor and at least two of said fluid chambers, means for regulating the operation of the valve for the motor to cause the motor to drive the driven shaft in either forward or reverse direction, and a valve for controlling the flow of fluid through said chambers, said valve in closed position operating to fluid lock said transmission to effect direct drive.

18. A torque-sensitive fluid transmission comprising a driving member. a fluid pump connected to said driving member, a driven member, a motor connected to said driven member, said motor being operated by fluid flow from the pump for driving said driven member, conduits joining the pump and motor for conducting fluid therebetween, a casing rotatably mounted around said pump, motor and conduits, means for moving said pump into and out of concentric relation with said driving member to vary the pumping action on the fluid, and a counterbalancing device movable relative to said pump to maintain dynamic balance-in the transmission.

- DANIEL F. McGILL. 

